Average prices in all regions dropped in the latest week led by a plunge of 6.9 cents to $4.067 in California.
The national average price is at its highest level since Sept. 15, 2008.
The price is the highest since Sep. 29, 2008, when it was $3.969.
Advances of 8 to 9 cents a gallon were common during the week of Feb. 28.
The price is the highest since Oct. 13, 2008, when it was $3.659.
Consumer, safety and labor groups have petitioned a federal court for permission to pursue a third round of litigation to overturn the hours of service rule.
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